History.js polyfill for ember.js

(function() {
  var get = Ember.get, set = Ember.set;
  var popstateFired = false;
  Ember.HistoryJsLocation = Ember.Object.extend({
    init: function() {
      set(this, 'location', get(this, 'location') || window.location);
      this._initialUrl = this.getURL();
      this.initState();
    },
    initState: function() {
      this.replaceState(this.formatURL(this.getURL()));
      set(this, 'history', window.History);
    },
    rootURL: '/',
    getURL: function() {
      var rootURL = get(this, 'rootURL'),
        url = get(this, 'location').pathname;
      rootURL = rootURL.replace(/\/$/, '');
      url = url.replace(rootURL, '');
      return url;
    },
    setURL: function(path) {
      path = this.formatURL(path);
      if (this.getState() && this.getState().path !== path) {
        this.pushState(path);
      }
    },
    replaceURL: function(path) {
      path = this.formatURL(path);
      if (this.getState() && this.getState().path !== path) {
        this.replaceState(path);
      }
    },
    getState: function() {
      return get(this, 'history').getState().data;
    },
    pushState: function(path) {
      History.pushState({ path: path }, null, path);
    },
    replaceState: function(path) {
      History.replaceState({ path: path }, null, path);
    },
    onUpdateURL: function(callback) {
      var guid = Ember.guidFor(this),
        self = this;
      Ember.$(window).bind('popstate.ember-location-'+guid, function(e) {
        if(!popstateFired) {
          popstateFired = true;
          if (self.getURL() === self._initialUrl) { return; }
        }
        callback(self.getURL());
      });
    },
    formatURL: function(url) {
      var rootURL = get(this, 'rootURL');
      if (url !== '') {
        rootURL = rootURL.replace(/\/$/, '');
      }
      return rootURL + url;
    },
    willDestroy: function() {
      var guid = Ember.guidFor(this);
      Ember.$(window).unbind('popstate.ember-location-'+guid);
    }
  });
  Ember.Location.registerImplementation('historyJs', Ember.HistoryJsLocation);
})();